The present invention relates to an improved top wear plate for a size reducing machine. In particular, to a serrated top wear plate that includes a plurality of pointed edges against which waste material is size reduced after being impacted by a hammer of a size reducing machine.
Size reducing machines, like tub grinders, rotary hammermills, and the like, typically consist of a rotor rotated about a central shaft by a motor. The rotor contains a plurality of hammers that further include inserts that impact waste material introduced into the machine. The waste material travels along the floor of the machine and onto a top wear plate. As the waste material enters the path of the rotor, the hammers strike the waste material against the top plate. The edge of the top plate comprises a primary wear surface, and serves the function of initially size reducing the waste material. In other words, the amount of separation between the top plate and the hammer tips in large part determines the size of the initial break in the waste material.
After initial impact the partially size reduced material is typically directed toward a side wear plate and then into the partially enclosed rotor area, whereupon the hammers continue to impact the material until the material reaches a size sufficient to allow the waste material to pass through a screen thereby exiting the size reducing machine.
In the prior art, the top plate consists of a long rectangular piece of plate steel material, or series of plates, that span the length of the rotor area of the size reducing machine. The leading edge of the top plate is reinforced with a hard-face weld, to provide better wear resistance.
The prior art design suffers from not only wear problems, but the flat planer edge of the top plate requires the waste material to fracture along the entire length of the leading edge of the top plate. This creates resistance to the break up of the material and increases the amount of force required to initially size reduce the waste material. Thus, a need exists for a size reducing machine that uses a top plate the allows for more efficient initial size reduction of waste material.